1. Field of the Invention
The present invention relates generally to a multiple implement towing arrangement and, more specifically, to caster wheel structure for such a towing arrangement.
2. Related Art
Multiple implement hitches of the type shown in U.S. Pat. No. 4,260,172 utilize a series of lift legs mounted at the rear of the implements and supporting in-line transport wheels having fore-and-aft extending axes of rotation for endwise towing. High side loading often is experienced by the lift legs and tires during turns, especially when four or more of the implements are ganged for towing, and excessive tire scuffing and tire wear result.
Some endwise transport systems use caster wheels at both the front and rear of the towed gang. Although the caster wheels help reduce the high side loads, some instability may be introduced which can make transport more difficult. Locking of the caster wheels in an in-line position is advantageous for stability at times such as during backing of the implements in the endwise position. A caster brake or other shimmy reducing device is required to prevent wheel oscillation during transport.
Another problem encountered with some endwise transport systems which utilize caster wheels involves firmly supporting the wheels when they are raised for normal field operations so that unwanted rocking is prevented. For example, on grain drill endwise transport systems, the caster wheels are typically located adjacent a platform by the grain hoppers so that it is necessary to secure the wheels against castering. Some systems utilize a pin arrangement which can be difficult and time consuming to use.